I read about the new Pentax K-3 (I read about all manufacturers and what they launch as new gear) and realized that I should give it a try on the new Pentax K-3. Rented the camera and the Pentax 300mm F4.0 DA lens and went out to shoot birds flying, my preferred subject. I was very well impressed about the camera and more specifically about its auto-focusing system. The camera is able to track birds flying in the sky and on top of high contrast background. Wow! It seems unbelievable to me that that is possible, since Canon and Nikon does not do that very well. I rented the camera two more times to make sure my findings were correct and could be replicated again, only now I am shooting all day for four days in the row the same subject, lighting, technique and so on. The camera respond the same way, auto-focusing tracking system is amazing, yes it tracks not only on those two different backgrounds but when bushes or posts or anything gets in front of birds flying the camera ignores the interference and maintains focus! Wow! I send the rental cameras back and bought a new one for me.Got the new camera and the new lens and all my canon gear and went to Bosque Del Apache to shoot birds flying. Four days to do just that. Went there and I am having a ball with my new camera and the lens and Canon is left behind on my car all the time. At the third day I went to the hotel and decided to share my experiences with friends and one of them told me that Pentax has created a new firmware the 1.02 for the camera saying that the auto-focus system had improved with that version. I decided to upgrade to that firmware to confirm what was said and next day went shooting.To my dismay! The camera was simply HORRIBLE! I could not believe what just had happened! The camera now is hunting a lot! And my keepers which was about 90 percent, now is less then 10! I was sooooooooooooo disappointed and frustrated! I was shooting the same subject, on the same place, at the same time, with the same light, and the same techniques, with the same lens! UNBELIVABLE! Pentax says the speed of auto-focusing has improved! NO! not only has not improved it got way worst! Guys do not upgrade to the 1.02! I sent my camera back to B&H in an attempt to get a new one with the firmware 1.0 and that is going to be it for long time. I am contemplating in sending everything back and forget that one day I purchase Pentax, so bad the upgrade went. I will test the new camera again and if it responds the way it was before, which it should, I will keep the camera and not upgrade to any firmware soon. Oh, and I forgot to mention the camera (four that went in my hands, 3 rented ones and the new one) one rented camera and the new one had many crazy lock ups that happen with my battery grip and without. Pentax says that various issues and the one with the battery grip has been fixed. I say NO, it did not fix anything, on the contrary. The AF tracking got way worst, also the AF button on the back of the camera after firmware 1.02 upgrade has been done got locked few times and other funny reactions happened as well. I have to turn the camera off and on to stop the lock-up. Interesting enough I used two other rented Pentaxes K3over different weekends, one at a time, and none of them had any issues, or behaved differently with the focus tracking, so it seems to me that there are some issues with hardware and software that Pentax is unable to detect yet. I hope they do, but it seems that nobody cares after I call them here in the US and the customer service guy told me that tech people are only available in Japan. I am writing a letter for everybody at Pentax in an attempt to have this camera in good stands and fixed. I will wait for my new camera to arrive, check if will have the firmware 1.0 test it and see how it goes... will keep you posted.Best regards,Zeca